I upped my 4-jet to a total of '08 but clean with reduced pressure, the idea being to avoid blasting water down into the backing. I cleaned a 30+ year old Axminster at 150psi today, came up lovely and after a quick turbo-dry was touch dry by the time I left
I have a twin jet downgraded to '04 total jetting which I run at higher pressures when needed to apply a bit of brute force. Got myself out of the doo-doo with it the other day, started to extract an Axminster which had compacted soil washing up in tide marks using the low-impact 4-jet setup. Switched to the 2 jets and cranked it up and it sorted the problem.
You can't use just one wand configuration to cover everything